1
|
Pellegrino M, Giordano F, De Amicis F, Marra M, Tucci P, Marsico S, Aquaro S. HIV-1 Structural Proteins or Cell-Signaling Factors? That Is the Question! Curr Issues Mol Biol 2024; 46:5100-5116. [PMID: 38920978 PMCID: PMC11202448 DOI: 10.3390/cimb46060306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 05/20/2024] [Accepted: 05/21/2024] [Indexed: 06/27/2024] Open
Abstract
The biological activity of structural HIV-1 proteins is not limited to ensuring a productive viral infection but also interferes with cellular homeostasis through intra- and extracellular signaling activation. This interference induces genomic instability, increases the lifespan of the infected cell by inhibiting apoptosis, and subverts cell senescence, resulting in unrestricted cell proliferation. HIV structural proteins are present in a soluble form in the lymphoid tissues and blood of infected individuals, even without active viral replication. The HIV matrix protein p17, the envelope glycoprotein gp120, the transenvelope protein gp41, and the capsid protein p24 interact with immune cells and deregulate the biological activity of the immune system. The biological activity of HIV structural proteins is also demonstrated in endothelial cells and some tumor cell lines, confirming the ability of viral proteins to promote cell proliferation and cancer progression, even in the absence of active viral replication. This review corroborates the hypothesis that HIV structural proteins, by interacting with different cell types, contribute to creating a microenvironment that is favorable to the evolution of cancerous pathologies not classically related to AIDS.
Collapse
Affiliation(s)
| | | | | | | | | | - Stefania Marsico
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Arcavacata di Rende, Italy; (M.P.)
| | | |
Collapse
|
2
|
Shah R, Gallardo CM, Jung YH, Clock B, Dixon JR, McFadden WM, Majumder K, Pintel DJ, Corces VG, Torbett BE, Tedbury PR, Sarafianos SG. Activation of HIV-1 proviruses increases downstream chromatin accessibility. iScience 2022; 25:105490. [PMID: 36505924 PMCID: PMC9732416 DOI: 10.1016/j.isci.2022.105490] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 09/15/2022] [Accepted: 10/31/2022] [Indexed: 11/09/2022] Open
Abstract
It is unclear how the activation of HIV-1 transcription affects chromatin structure. We interrogated chromatin organization both genome-wide and nearby HIV-1 integration sites using Hi-C and ATAC-seq. In conjunction, we analyzed the transcription of the HIV-1 genome and neighboring genes. We found that long-range chromatin contacts did not differ significantly between uninfected cells and those harboring an integrated HIV-1 genome, whether the HIV-1 genome was actively transcribed or inactive. Instead, the activation of HIV-1 transcription changes chromatin accessibility immediately downstream of the provirus, demonstrating that HIV-1 can alter local cellular chromatin structure. Finally, we examined HIV-1 and neighboring host gene transcripts with long-read sequencing and found populations of chimeric RNAs both virus-to-host and host-to-virus. Thus, multiomics profiling revealed that the activation of HIV-1 transcription led to local changes in chromatin organization and altered the expression of neighboring host genes.
Collapse
Affiliation(s)
- Raven Shah
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30329, USA
- Children’s Healthcare of Atlanta, Atlanta, GA 30329, USA
| | - Christian M. Gallardo
- Center for Immunity and Immunotherapies, Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Yoonhee H. Jung
- Department of Biology, Emory University, Atlanta, GA 30329, USA
| | - Ben Clock
- Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Jesse R. Dixon
- Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - William M. McFadden
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30329, USA
- Children’s Healthcare of Atlanta, Atlanta, GA 30329, USA
| | - Kinjal Majumder
- Institute for Molecular Virology and McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - David J. Pintel
- Department of Molecular Microbiology and Immunology, Christopher S. Bond Life Sciences Center, University of Missouri School of Medicine, Columbia, MO 65211, USA
| | | | - Bruce E. Torbett
- Center for Immunity and Immunotherapies, Seattle Children’s Research Institute, Seattle, WA 98101, USA
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98101, USA
| | - Philip R. Tedbury
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30329, USA
- Children’s Healthcare of Atlanta, Atlanta, GA 30329, USA
| | - Stefan G. Sarafianos
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30329, USA
- Children’s Healthcare of Atlanta, Atlanta, GA 30329, USA
| |
Collapse
|
3
|
Xu S, Sun L, Zalloum WA, Huang T, Zhang X, Ding D, Shao X, Jiang X, Zhao F, Cocklin S, De Clercq E, Pannecouque C, Dick A, Liu X, Zhan P. Discovery and Mechanistic Investigation of Piperazinone Phenylalanine Derivatives with Terminal Indole or Benzene Ring as Novel HIV-1 Capsid Modulators. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238415. [PMID: 36500508 PMCID: PMC9739877 DOI: 10.3390/molecules27238415] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 11/26/2022] [Accepted: 11/29/2022] [Indexed: 12/05/2022]
Abstract
HIV-1 capsid (CA) performs multiple roles in the viral life cycle and is a promising target for antiviral development. In this work, we describe the design, synthesis, assessment of antiviral activity, and mechanistic investigation of 20 piperazinone phenylalanine derivatives with a terminal indole or benzene ring. Among them, F2-7f exhibited moderate anti-HIV-1 activity with an EC50 value of 5.89 μM, which was slightly weaker than the lead compound PF74 (EC50 = 0.75 μM). Interestingly, several compounds showed a preference for HIV-2 inhibitory activity, represented by 7f with an HIV-2 EC50 value of 4.52 μM and nearly 5-fold increased potency over anti-HIV-1 (EC50 = 21.81 μM), equivalent to PF74 (EC50 = 4.16 μM). Furthermore, F2-7f preferred to bind to the CA hexamer rather than to the monomer, similar to PF74, according to surface plasmon resonance results. Molecular dynamics simulation indicated that F2-7f and PF74 bound at the same site. Additionally, we computationally analyzed the ADMET properties for 7f and F2-7f. Based on this analysis, 7f and F2-7f were predicted to have improved drug-like properties and metabolic stability over PF74, and no toxicities were predicted based on the chemotype of 7f and F2-7f. Finally, the experimental metabolic stability results of F2-7f in human liver microsomes and human plasma moderately correlated with our computational prediction. Our findings show that F2-7f is a promising small molecule targeting the HIV-1 CA protein with considerable development potential.
Collapse
Affiliation(s)
- Shujing Xu
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Shandong University, 44 West Culture Road, Jinan 250012, China
| | - Lin Sun
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Shandong University, 44 West Culture Road, Jinan 250012, China
- Department of Pharmacy, Qilu Hospital of Shandong University, Jinan 250012, China
| | - Waleed A. Zalloum
- Department of Pharmacy, Faculty of Health Science, American University of Madaba, P.O. Box 2882, Amman 11821, Jordan
| | - Tianguang Huang
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Shandong University, 44 West Culture Road, Jinan 250012, China
| | - Xujie Zhang
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Shandong University, 44 West Culture Road, Jinan 250012, China
| | - Dang Ding
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Shandong University, 44 West Culture Road, Jinan 250012, China
| | - Xiaoyu Shao
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Shandong University, 44 West Culture Road, Jinan 250012, China
| | - Xiangyi Jiang
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Shandong University, 44 West Culture Road, Jinan 250012, China
| | - Fabao Zhao
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Shandong University, 44 West Culture Road, Jinan 250012, China
| | - Simon Cocklin
- Specifica Inc., The Santa Fe Railyard, 1607 Alcaldesa Street, Santa Fe, NM 87501, USA
| | - Erik De Clercq
- Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, K.U. Leuven, Herestraat 49 Postbus 1043 (09.A097), B-3000 Leuven, Belgium
| | - Christophe Pannecouque
- Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, K.U. Leuven, Herestraat 49 Postbus 1043 (09.A097), B-3000 Leuven, Belgium
- Correspondence: (C.P.); (A.D.); (X.L.); (P.Z.)
| | - Alexej Dick
- Department of Biochemistry & Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
- Correspondence: (C.P.); (A.D.); (X.L.); (P.Z.)
| | - Xinyong Liu
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Shandong University, 44 West Culture Road, Jinan 250012, China
- Correspondence: (C.P.); (A.D.); (X.L.); (P.Z.)
| | - Peng Zhan
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Shandong University, 44 West Culture Road, Jinan 250012, China
- Correspondence: (C.P.); (A.D.); (X.L.); (P.Z.)
| |
Collapse
|
4
|
Wang W, Li Y, Zhang Z, Wei W. Human immunodeficiency virus-1 core: The Trojan horse in virus–host interaction. Front Microbiol 2022; 13:1002476. [PMID: 36106078 PMCID: PMC9465167 DOI: 10.3389/fmicb.2022.1002476] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 08/04/2022] [Indexed: 11/13/2022] Open
Abstract
Human immunodeficiency virus-1 (HIV-1) is the major cause of acquired immunodeficiency syndrome (AIDs) worldwide. In HIV-1 infection, innate immunity is the first defensive line for immune recognition and viral clearance to ensure the normal biological function of the host cell and body health. Under the strong selected pressure generated by the human body over thousands of years, HIV has evolved strategies to counteract and deceive the innate immune system into completing its lifecycle. Recently, several studies have demonstrated that HIV capsid core which is thought to be a protector of the cone structure of genomic RNA, also plays an essential role in escaping innate immunity surveillance. This mini-review summarizes the function of capsid in viral immune evasion, and the comprehensive elucidation of capsid-host cell innate immunity interaction could promote our understanding of HIV-1’s pathogenic mechanism and provide insights for HIV-1 treatment in clinical therapy.
Collapse
Affiliation(s)
- Wei Wang
- Institute of Virology and AIDS Research, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Yan Li
- Institute of Virology and AIDS Research, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Zhe Zhang
- Institute of Virology and AIDS Research, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Wei Wei
- Institute of Virology and AIDS Research, The First Hospital of Jilin University, Changchun, Jilin, China
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Institute of Translational Medicine, First Hospital, Jilin University, Changchun, Jilin, China
- *Correspondence: Wei Wei,
| |
Collapse
|
5
|
Allosteric Integrase Inhibitor Influences on HIV-1 Integration and Roles of LEDGF/p75 and HDGFL2 Host Factors. Viruses 2022; 14:v14091883. [PMID: 36146690 PMCID: PMC9502684 DOI: 10.3390/v14091883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/11/2022] [Accepted: 08/24/2022] [Indexed: 02/01/2023] Open
Abstract
Allosteric integrase (IN) inhibitors (ALLINIs), which are promising preclinical compounds that engage the lens epithelium-derived growth factor (LEDGF)/p75 binding site on IN, can inhibit different aspects of human immunodeficiency virus 1 (HIV-1) replication. During the late phase of replication, ALLINIs induce aberrant IN hyper-multimerization, the consequences of which disrupt IN binding to genomic RNA and virus particle morphogenesis. During the early phase of infection, ALLINIs can suppress HIV-1 integration into host genes, which is also observed in LEDGF/p75-depelted cells. Despite this similarity, the roles of LEDGF/p75 and its paralog hepatoma-derived growth factor like 2 (HDGFL2) in ALLINI-mediated integration retargeting are untested. Herein, we mapped integration sites in cells knocked out for LEDGF/p75, HDGFL2, or both factors, which revealed that these two proteins in large part account for ALLINI-mediated integration retargeting during the early phase of infection. We also determined that ALLINI-treated viruses are defective during the subsequent round of infection for integration into genes associated with speckle-associated domains, which are naturally highly targeted for HIV-1 integration. Class II IN mutant viruses with alterations distal from the LEDGF/p75 binding site moreover shared this integration retargeting phenotype. Altogether, our findings help to inform the molecular bases and consequences of ALLINI action.
Collapse
|
6
|
Localization and functions of native and eGFP-tagged capsid proteins in HIV-1 particles. PLoS Pathog 2022; 18:e1010754. [PMID: 35951676 PMCID: PMC9426931 DOI: 10.1371/journal.ppat.1010754] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 08/30/2022] [Accepted: 07/21/2022] [Indexed: 12/24/2022] Open
Abstract
In infectious HIV-1 particles, the capsid protein (CA) forms a cone-shaped shell called the capsid, which encases the viral ribonucleoprotein complex (vRNP). Following cellular entry, the capsid is disassembled through a poorly understood process referred to as uncoating, which is required to release the reverse transcribed HIV-1 genome for integration into host chromatin. Whereas single virus imaging using indirect CA labeling techniques suggested uncoating to occur in the cytoplasm or at the nuclear pore, a recent study using eGFP-tagged CA reported uncoating in the nucleus. To delineate the HIV-1 uncoating site, we investigated the mechanism of eGFP-tagged CA incorporation into capsids and the utility of this fluorescent marker for visualizing HIV-1 uncoating. We find that virion incorporated eGFP-tagged CA is effectively excluded from the capsid shell, and that a subset of the tagged CA is vRNP associated. These results thus imply that eGFP-tagged CA is not a direct marker for capsid uncoating. We further show that native CA co-immunoprecipitates with vRNP components, providing a basis for retention of eGFP-tagged and untagged CA by sub-viral complexes in the nucleus. Moreover, we find that functional viral replication complexes become accessible to integrase-interacting host factors at the nuclear pore, leading to inhibition of infection and demonstrating capsid permeabilization prior to nuclear import. Finally, we find that HIV-1 cores containing a mixture of wild-type and mutant CA interact differently with cytoplasmic versus nuclear pools of the CA-binding host cofactor CPSF6. Our results suggest that capsid remodeling (including a loss of capsid integrity) is the predominant pathway for HIV-1 nuclear entry and provide new insights into the mechanism of CA retention in the nucleus via interaction with vRNP components. The timing, location and mechanisms of HIV-1 capsid disassembly which is referred to as uncoating remains unclear. Direct labeling of HIV-1 capsids, by incorporating a few green fluorescent proteins (GFP) tagged capsid protein (CA) into virions allows to image the spatio-temporal loss of HIV-1 CA during virus infection. However, the localization and functions of a few virion incorporated eGFP-tagged CA proteins remain unclear, since <50% of virus packaged CA proteins participate to form the conical capsid shell that protects the HIV-1 genome. Here we developed several approaches to test the localization and function of eGFP-tagged CA proteins in virions. We found that eGFP-tagged CA proteins are excluded from the conical capsid shell and that a subset of these proteins is associated with the viral ribonucleoprotein complex (vRNPs), through direct interactions between CA and vRNP components. eGFP-tagged CA is retained in the nucleus by virtue of vRNP association and is unlikely to report on HIV-1 capsid disassembly. We also found that HIV-1 capsids become permeabilized and are remodeled during their transport into the nucleus. Our study provides new insights into the ability of CA to interact with vRNPs for its retention in the nucleus and highlights capsid remodeling as a preferred pathway for HIV-1 entry into the nucleus.
Collapse
|
7
|
Intranuclear Positions of HIV-1 Proviruses Are Dynamic and Do Not Correlate with Transcriptional Activity. mBio 2022; 13:e0325621. [PMID: 35012348 PMCID: PMC8749423 DOI: 10.1128/mbio.03256-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The relationship between spatiotemporal distribution of HIV-1 proviruses and their transcriptional activity is not well understood. To elucidate the intranuclear positions of transcriptionally active HIV-1 proviruses, we utilized an RNA fluorescence in situ hybridization assay and RNA stem loops that bind to fluorescently labeled bacterial protein (Bgl-mCherry) to specifically detect HIV-1 transcription sites. Initially, transcriptionally active wild-type proviruses were located closer to the nuclear envelope (NE) than expected by random chance in HeLa (∼1.4 μm) and CEM-SS T cells (∼0.9 μm). Disrupting interactions between HIV-1 capsid and host cleavage and polyadenylation specificity factor (CPSF6) resulted in localization of proviruses to lamina-associated domains (LADs) adjacent to the NE in HeLa cells (∼0.9 - 1.0 μm); however, in CEM-SS T cells, there was little or no shift toward the NE (∼0.9 μm), indicating cell-type differences in the locations of transcriptionally active proviruses. The distance from the NE was not correlated with transcriptional activity, and transcriptionally active proviruses were randomly distributed throughout the HeLa cell after several cell divisions, indicating that the intranuclear locations of the chromosomal sites of integration are dynamic. After nuclear import HIV-1 cores colocalized with nuclear speckles, nuclear domains enriched in pre-mRNA splicing factors, but transcriptionally active proviruses detected 20 h after infection were mostly located outside but near nuclear speckles, suggesting a dynamic relationship between the speckles and integration sites. Overall, these studies establish that the nuclear distribution of HIV-1 proviruses is dynamic and the distance between HIV-1 proviruses and the NE does not correlate with transcriptional activity. IMPORTANCE HIV-1 integrates its genomic DNA into the chromosomes of the infected cell, but how it selects the site of integration and the impact of their location in the 3-dimensional nuclear space is not well understood. Here, we examined the nuclear locations of proviruses 1 and 5 days after infection and found that integration sites are first located near the nuclear envelope but become randomly distributed throughout the nucleus after a few cell divisions, indicating that the locations of the chromosomal sites of integration that harbor transcriptionally active proviruses are dynamic. We also found that the distance from the nuclear envelope to the integration site is cell-type dependent and does not correlate with proviral transcription activity. Finally, we observed that HIV-1 cores were localized to nuclear speckles shortly after nuclear import, but transcriptionally active proviruses were located adjacent to nuclear speckles. Overall, these studies provide insights into HIV-1 integration site selection and their effect on transcription activities.
Collapse
|
8
|
Guedán A, Caroe ER, Barr GCR, Bishop KN. The Role of Capsid in HIV-1 Nuclear Entry. Viruses 2021; 13:1425. [PMID: 34452291 PMCID: PMC8402913 DOI: 10.3390/v13081425] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/16/2021] [Accepted: 07/17/2021] [Indexed: 12/19/2022] Open
Abstract
HIV-1 can infect non-dividing cells. The nuclear envelope therefore represents a barrier that HIV-1 must traverse in order to gain access to the host cell chromatin for integration. Hence, nuclear entry is a critical step in the early stages of HIV-1 replication. Following membrane fusion, the viral capsid (CA) lattice, which forms the outer face of the retroviral core, makes numerous interactions with cellular proteins that orchestrate the progress of HIV-1 through the replication cycle. The ability of CA to interact with nuclear pore proteins and other host factors around the nuclear pore determines whether nuclear entry occurs. Uncoating, the process by which the CA lattice opens and/or disassembles, is another critical step that must occur prior to integration. Both early and delayed uncoating have detrimental effects on viral infectivity. How uncoating relates to nuclear entry is currently hotly debated. Recent technological advances have led to intense discussions about the timing, location, and requirements for uncoating and have prompted the field to consider alternative uncoating scenarios that presently focus on uncoating at the nuclear pore and within the nuclear compartment. This review describes recent advances in the study of HIV-1 nuclear entry, outlines the interactions of the retroviral CA protein, and discusses the challenges of investigating HIV-1 uncoating.
Collapse
Affiliation(s)
| | | | | | - Kate N. Bishop
- Retroviral Replication Laboratory, The Francis Crick Institute, London NW1 1AT, UK; (A.G.); (E.R.C.); (G.C.R.B.)
| |
Collapse
|
9
|
Structure, Function, and Interactions of the HIV-1 Capsid Protein. Life (Basel) 2021; 11:life11020100. [PMID: 33572761 PMCID: PMC7910843 DOI: 10.3390/life11020100] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 11/30/2022] Open
Abstract
The capsid (CA) protein of the human immunodeficiency virus type 1 (HIV-1) is an essential structural component of a virion and facilitates many crucial life cycle steps through interactions with host cell factors. Capsid shields the reverse transcription complex from restriction factors while it enables trafficking to the nucleus by hijacking various adaptor proteins, such as FEZ1 and BICD2. In addition, the capsid facilitates the import and localization of the viral complex in the nucleus through interaction with NUP153, NUP358, TNPO3, and CPSF-6. In the later stages of the HIV-1 life cycle, CA plays an essential role in the maturation step as a constituent of the Gag polyprotein. In the final phase of maturation, Gag is cleaved, and CA is released, allowing for the assembly of CA into a fullerene cone, known as the capsid core. The fullerene cone consists of ~250 CA hexamers and 12 CA pentamers and encloses the viral genome and other essential viral proteins for the next round of infection. As research continues to elucidate the role of CA in the HIV-1 life cycle and the importance of the capsid protein becomes more apparent, CA displays potential as a therapeutic target for the development of HIV-1 inhibitors.
Collapse
|
10
|
Bedwell GJ, Engelman AN. Factors that mold the nuclear landscape of HIV-1 integration. Nucleic Acids Res 2021; 49:621-635. [PMID: 33337475 PMCID: PMC7826272 DOI: 10.1093/nar/gkaa1207] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 11/26/2020] [Indexed: 12/17/2022] Open
Abstract
The integration of retroviral reverse transcripts into the chromatin of the cells that they infect is required for virus replication. Retroviral integration has far-reaching consequences, from perpetuating deadly human diseases to molding metazoan evolution. The lentivirus human immunodeficiency virus 1 (HIV-1), which is the causative agent of the AIDS pandemic, efficiently infects interphase cells due to the active nuclear import of its preintegration complex (PIC). To enable integration, the PIC must navigate the densely-packed nuclear environment where the genome is organized into different chromatin states of varying accessibility in accordance with cellular needs. The HIV-1 capsid protein interacts with specific host factors to facilitate PIC nuclear import, while additional interactions of viral integrase, the enzyme responsible for viral DNA integration, with cellular nuclear proteins and nucleobases guide integration to specific chromosomal sites. HIV-1 integration favors transcriptionally active chromatin such as speckle-associated domains and disfavors heterochromatin including lamina-associated domains. In this review, we describe virus-host interactions that facilitate HIV-1 PIC nuclear import and integration site targeting, highlighting commonalities among factors that participate in both of these steps. We moreover discuss how the nuclear landscape influences HIV-1 integration site selection as well as the establishment of active versus latent virus infection.
Collapse
Affiliation(s)
- Gregory J Bedwell
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
11
|
Engelman AN. HIV Capsid and Integration Targeting. Viruses 2021; 13:125. [PMID: 33477441 PMCID: PMC7830116 DOI: 10.3390/v13010125] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 12/20/2022] Open
Abstract
Integration of retroviral reverse transcripts into the chromosomes of the cells that they infect is required for efficient viral gene expression and the inheritance of viral genomes to daughter cells. Before integration can occur, retroviral reverse transcription complexes (RTCs) must access the nuclear environment where the chromosomes reside. Retroviral integration is non-random, with different types of virus-host interactions impacting where in the host chromatin integration takes place. Lentiviruses such as HIV efficiently infect interphase cells because their RTCs have evolved to usurp cellular nuclear import transport mechanisms, and research over the past decade has revealed specific interactions between the HIV capsid protein and nucleoporin (Nup) proteins such as Nup358 and Nup153. The interaction of HIV capsid with cleavage and polyadenylation specificity factor 6 (CPSF6), which is a component of the cellular cleavage and polyadenylation complex, helps to dictate nuclear import as well as post-nuclear RTC invasion. In the absence of the capsid-CPSF6 interaction, RTCs are precluded from reaching nuclear speckles and gene-rich regions of chromatin known as speckle-associated domains, and instead mis-target lamina-associated domains out at the nuclear periphery. Highlighting this area of research, small molecules that inhibit capsid-host interactions important for integration site targeting are highly potent antiviral compounds.
Collapse
Affiliation(s)
- Alan N. Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; ; Tel.: +1-617-632-4361
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
12
|
Li W, Singh PK, Sowd GA, Bedwell GJ, Jang S, Achuthan V, Oleru AV, Wong D, Fadel HJ, Lee K, KewalRamani VN, Poeschla EM, Herschhorn A, Engelman AN. CPSF6-Dependent Targeting of Speckle-Associated Domains Distinguishes Primate from Nonprimate Lentiviral Integration. mBio 2020; 11:e02254-20. [PMID: 32994325 PMCID: PMC7527728 DOI: 10.1128/mbio.02254-20] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 08/28/2020] [Indexed: 12/19/2022] Open
Abstract
Lentiviral DNA integration favors transcriptionally active chromatin. We previously showed that the interaction of human immunodeficiency virus type 1 (HIV-1) capsid with cleavage and polyadenylation specificity factor 6 (CPSF6) localizes viral preintegration complexes (PICs) to nuclear speckles for integration into transcriptionally active speckle-associated domains (SPADs). In the absence of the capsid-CPSF6 interaction, PICs uncharacteristically accumulate at the nuclear periphery and target heterochromatic lamina-associated domains (LADs) for integration. The integrase-binding protein lens epithelium-derived growth factor (LEDGF)/p75 in contrast to CPSF6 predominantly functions to direct HIV-1 integration to interior regions of transcription units. Though CPSF6 and LEDGF/p75 can reportedly interact with the capsid and integrase proteins of both primate and nonprimate lentiviruses, the extents to which these different viruses target SPADs versus LADs, as well as their dependencies on CPSF6 and LEDGF/p75 for integration targeting, are largely unknown. Here, we mapped 5,489,157 primate and nonprimate lentiviral integration sites in HEK293T and Jurkat T cells as well as derivative cells that were knocked out or knocked down for host factor expression. Despite marked preferences of all lentiviruses to target genes for integration, nonprimate lentiviruses only marginally favored SPADs, with corresponding upticks in LAD-proximal integration. While LEDGF/p75 knockout disrupted the intragenic integration profiles of all lentiviruses similarly, CPSF6 depletion specifically counteracted SPAD integration targeting by primate lentiviruses. CPSF6 correspondingly failed to appreciably interact with nonprimate lentiviral capsids. We conclude that primate lentiviral capsid proteins evolved to interact with CPSF6 to optimize PIC localization for integration into transcriptionally active SPADs.IMPORTANCE Integration is the defining step of the retroviral life cycle and underlies the inability to cure HIV/AIDS through the use of intensified antiviral therapy. The reservoir of latent, replication-competent proviruses that forms early during HIV infection reseeds viremia when patients discontinue medication. HIV cure research is accordingly focused on the factors that guide provirus formation and associated chromatin environments that regulate transcriptional reactivation, and studies of orthologous infectious agents such as nonprimate lentiviruses can inform basic principles of HIV biology. HIV-1 utilizes the integrase-binding protein LEDGF/p75 and the capsid interactor CPSF6 to target speckle-associated domains (SPADs) for integration. However, the extent to which these two host proteins regulate integration of other lentiviruses is largely unknown. Here, we mapped millions of retroviral integration sites in cell lines that were depleted for LEDGF/p75 and/or CPSF6. Our results reveal that primate lentiviruses uniquely target SPADs for integration in a CPSF6-dependent manner.
Collapse
Affiliation(s)
- Wen Li
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Parmit K Singh
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Gregory A Sowd
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Gregory J Bedwell
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Sooin Jang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Vasudevan Achuthan
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Amarachi V Oleru
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Doris Wong
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Hind J Fadel
- Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - KyeongEun Lee
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Vineet N KewalRamani
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Eric M Poeschla
- Division of Infectious Diseases, University of Colorado Denver School of Medicine, Aurora, Colorado, USA
| | - Alon Herschhorn
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|